1. Field of the Invention
The present invention relates to a multipurpose hinge apparatus having an automatic return function, and more particularly, to a multipurpose hinge apparatus having a stable and reliable mechanism of setting multi-step automatic return speed which can be applied in any hinge apparatus whose rotational axis is same or different from that of a door such as a left/right rotating door hinge apparatus, or an up/down rotational hinge apparatus.
2. Description of the Related Art
A hinge apparatus is an apparatus which makes two members spaced from each other or folded one over another according to necessity. A representative example of the hinge apparatus is a left/right rotational hinge apparatus including a horizontal actuator which is used between a door and window frame, or an up/down rotational hinge apparatus including a vertical actuator which is used for a refrigerator, a mobile phone, or a notebook computer.
A conventional hinge apparatus having an automatic return function is disclosed in Korean Laid-open Patent Publication No. 2001-0027832.
The conventional hinge apparatus includes a fixed hinge plate which is fixed to a door frame, and a movable hinge plate which is fixed on the door and moved together with the door as the door is opened and closed. Also, a plurality of cylindrical hinge knuckles are formed in the respective ends of the fixed hinge plate and the movable hinge plate, for binding the two hinge plates mutually. An upper cap is threadedly coupled with the fixed hinge knuckle, and a compression spring is installed in the lower portion of the upper cap, in order to provide a rotational force of the door.
In this case, when a door is opened, a conversion head is rotated together with the movable hinge knuckle and moves up and down according to repulsive power of the compression spring. The moving distance of the conversion head is limited by a guide pin which moves according to guidance of a guide elongate hole.
In the case of the conventional hinge apparatus, the conversion head is raised up according to rotation of the movable hinge plate when a door is opened, and the conversion head falls down by an elastic restoring force of the compression spring when the door is closed. Also, the hinge apparatus adjusts door closing speed by adjusting an amount of pressure oil flowing a return oil path, and first and second speed adjusting oil paths, and thus varying ascending and descending speed of the conversion head.
However, in the case of the hinge apparatus, the conversion head which ascends and descends according to rotation of the door are guided by a pair of guide pins. The guide pins are fixed to hinge knuckles. Also, a cylinder and the conversion head are incorporated in the knuckles of four or so. Accordingly, when the movable hinge knuckles receive big load and rotate for a long time, durability of the hinge apparatus is lowered and the structure is complicated. As a result, an assembly productivity deteriorates.
Also, since the compression spring for performing an automatic return of the door is arranged in the upper side of the conversion head, and a hydraulic circuit for adjusting return speed of the door is arranged in the lower side of the conversion head, it is difficult to reduce the total length of the hinge apparatus. Further, since lengthy space of arranging the compression spring is limited only in the upper side of the conversion head, a large restoring force cannot be provided for automatic return of the door. Accordingly, it is difficult to apply the compression spring to a large-scale door.
Also, the inner portion of the hinge apparatus and a mechanism of connecting the fixed portion and the movable portion of the hinge apparatus are applied only in the hinge apparatus. As a result, it is not possible to apply the hinge apparatus to a structure that the center of a door differs from that of the hinge apparatus.
Also, a fixing unit for temporarily fixing the door so that the door is not made to rotate at the state where the door is opened at a predetermined angle is not installed in the hinge apparatus. Accordingly, it is inconvenient for users to use the hinge apparatus.
Meanwhile, Korean Utility Model Registration No. 0271646 discloses a hinge door opening and closing apparatus in which a hydraulic door closer and a spring door closer are separately configured and the former and the latter are combined with each other.
Since the door opening and closing apparatus uses two combined door closers, it is difficult to make it compact. In this case, since a fixing unit for temporarily fixing the door so that the door is not made to rotate at the state where the door is opened at a predetermined angle is not also installed in the hinge apparatus, it is inconvenient for users to use the hinge door opening and closing apparatus. As a result, when a large external force such as a strong wind is applied to a door, it cannot prevent the door from being closed or opened at excessive speed.
Also, Korea Laid-open Patent Publication No. 2001-77142 discloses a door hinge apparatus which includes an upper hinge and a lower hinge adopting no hydraulic circuit to realize an automatic return function. Similarly to the above-described Korean Laid-open Patent Publication No. 2001-0027832, Korea Laid-open Patent Publication No. 2001-77142 does not have any excessive speed prevention function. Accordingly, it is impossible to adjust return speed according to necessity, since the return speed is determined by a cam diagram angle of only a predetermined return groove and speed set by a restoring force of a spring.
Meanwhile, Korean Utility Model Registration No. 238712 discloses a door hinge apparatus having a structure of ascending and descending a slider according to rotation of a stem in which the stem and the slider where the stem penetrates through a spiral elongate hole perforated on a main wall of the slider are combined through a bearing with both ends of a fixed pin, and a hydraulic control structure that an elastic spring is compressed according to descending of the slider and simultaneously oil is compressed where the compressed oil moves upwards through two oil paths and a check valve which are installed in a base and an oil tube.
However, in the case of the above-described hinge apparatus, the shapes and structures of the oil paths are very complicated, and thus workability is very bad. Also, when the door is opened, it is temporarily stopped and when a large external force such as a strong wind is applied to the door, excessive speed of the door cannot be prevented. Also, an oil containing space is deficient generally. Accordingly, when the door is opened and closed, each component of the hinge apparatus undergoes an overload or users should use a large force relatively.
Meanwhile, the conventional art has not provided an optimized structure of an up/down rotational door hinge apparatus which is applied in a Kimchi refrigerator for use in a storage device for storing a fermentation food such as Kimchi which is one of Korean traditional foods.